This invention relates generally to altering the dioptric power of corneal surfaces of the eye; more particularly it concerns insertion of multiple inert, intra-stroma, prostheses into cuts formed in outer portions of the cornea, to assist in neutralization of myopia, hyperopia, and correction of astigmatic conditions.
A nearsighted person, to see clearly at a distance, requires a convex plus power to focus the rays more forward to the macula. The opposite condition exists for the far-sighted individual who requires the distortion of the cornea to bend the rays of light closer to the macula posteriorly.
With the intra-stroma insertion into the cornea of a circular plastic mass, a bulging distortion of the anterior and/or posterior surfaces of the cornea can be produced, which can change the diopter power of the cornea, to favorably enhance the bending of rays of light to focus on the macula and create a clear image.
While efforts have been made to effect controlled bulging of the cornea, difficulties have been encountered in achieving corrections greater than 3.5 diopters of myopia, and to achieve the same status for hyperoptic corrections; and difficulties have been encountered in achieving refractively corrected astigmatism and prismatic distortions. There is continuing need for improvements in effecting controlled bulging of the cornea, in such manner as to achieve the desired corrections for astigmatism and for prismatic distortions.